Belt tightener



June '12, 1928.

T. ELLIOTT BELT TIGHTENER Filed Sept. 20, 1926 2 Sheets-Sheet I Fig.1

guwnl'oz THOMAS ELLIOT'II Fig. 2

T.- ELLI'OTT Juli? I2; 1925.

BELT TIGHTENER Filed-Sept; 20, 1926 2 Sheets-Sheet 2 F119. 4 THOMAS ELLIOTT;

Fig. 5

(Tum-C Patented June 12, 1928.

v UNITED STATES 'rnomns ELLIOTT, or

FATENT! W BIRMINGHAM, ALABAMA, nssrenon To contriun nrn nem eon- PANY, A conronn rron or nn nnwnnn;

BELT 'rren'rnnnn.

Application filed September 2Q, 1926. Serial No. 136,433.

My invention relatesto devices for regw' lating the tension imposed upon belts, bands, chains, and the like; and has particular reference to such devices which are intended to be used forregulatingwthe tension ofbelts and similar endless members such as are commonly used for the transmission of power from one rotatable elementto another.

A primary object of my present inventlon is to, produce a device of the said general character, having means for adjusting the position or positions of a-tension-regulating member or members, without the necessity of preliminary release of: said member or operativeposition partly by engagement of] the belt or the like with a ,part of said .means. The means by which the foregoingand other objects are accomplished by my invention, and the manner of their accompl sh ment, readily will be understood from the following description, or reference to the aceompanying drawings, which-depict a preferred embodiment of the invention, and in which??? Fig. 1 is a sideelevation ofmyimproved belt-tightener, the pulleys thereof being onset, and parts onlyiof the'belt being shown. Fig. 2 is a front elevation of the same, with the shell of the lower idler-pulley partly broken away. l Fig. 3 is aside elevation ofthe supportin bracket of the belt-tightener, shown on b alarger-scale; I 1

Fig. 4 is a sideelevation of the. slidein whichthe idler pulleys are mounted,-shown on the same scale as Fig. 3.

Fig. 5 is a front elevationof} thesame;

Referring now to thev drawings in detail, in which the various parts are indicated by the same referencecharactersin the difl'erent views, it will be .seen that my. improved heltrtightener comprises supportingbracket 7, a slide {Sladapted to ,co-act,there with, and tWL Similar idler pulleys 9 and 1 13.,

filth-at picieeti-ng in the all of said parts ordinarily being metalicastQ 1I10S. M

i lhe bracket 'i comprises a body portion having parallel, substantially planeimajor faces 11 andl2; having an extended portion 13,1ying in the same planes with said body portion, and terminating in a substantially plane, surface 14 which is substantially at right angles to the longitudinal center; line of saidextended portion, and tothe planes of the faces thereof; and v havingan offset portion 151 projecting substantially at right angles from the face 12 of said body portion, at theopposite end thereof from the extonded 'portion 14s Said olfsetportion 15 has a lip 16 projecting from its outer face at the upper edge thereoirand ha sa bolt hole 17- therein at the approximate'center'of the effect, so that the bracket 7 may be secured firmly in place on a suitable support, by the use of a singleb olt. f A slotf18, having parallel sides, and substantiallysemicircular closed ends, extendssfrqm near the upper, end of theextended portion 13 of the i bracket to a pointnear the lowerside of the body portion thereof.: I i 1 'lhe slide 8 comprises a body, portion of substantially the same thickness as the body portion of the bracket."and of-sucha idth asto fit slidablylin the slgt 18, said slide terminating at its upper-end in a right-angle ,oflset 19, having ascrew threaded opening .20 therein adapted for the reception of a thumb screw 21; and said having a bend at 22 and a reverse bend at 23,;so that the lower end of the slide parallel with its i pper end, and is oflsettherefromgin the 36 direction asofi'set 19., to iadistance approximately equal to the thickness ,Of the bracket? at and-near the slot 18. Atap- .provided'with aboss 24C, on the same side-as the offset 19, the distancethat said boss proproximately the middle otlthe bracket, it is outer face of the lower end of the slide, and

said boss ,having a cylindrical opening 25 formed axially thereof. and extending through the slidewAt.therespective sides of the lower end of the slide, it is provided with twosimilarears 26, therespectiveplane faces of which lie in the same planes .with

those of said lower-end, and saidlower end is provided with a boss .27, similar to bcss dream and having a cylindrical opening 28 formed axially thereof and extending through the slide, the outer plane face of said boss lying in substantially the same plane with the face of the upper end of the slide which is at the same side thereof as said boss.

The two idler pulleys 9 and 10 are each provided with doubleball bearings,and are similarly mounted upon the slide 8, pulley 9 being placed adjacent boss 24:, and pulley 10 being in line with boss 27, but at the opposite side of the slide therefrom. Each of I said pulleys has an annular flange 29 at its outer end, and has a cylindrical opening 30 extending axially through the pulley. Two similar ball bearings 31 are placed in said opening, at the respective ends of the pulley, being force-fitted or otherwise suitably secured in said opening. A cylindrical stud 32, having'a hexagonal head 33 at one end, and exteriorly screw threaded at the opposite end for the reception of a nut 34, has a cylindrical 0pening'35 formed axially thereof, said opening extending from the threaded end of the stud nearly to its head end, and being interiorly screw-threaded atits open end to receive the threaded shank of a grease cup 36. Between the ball bearing at the non-flanged end of the pulley and the adjacent portion of the slide 8 (which portion will be the plane end of boss 24 in the case of pulley 9, and the face of the lower end of the slide 8 in the case of pulley 10), is a washer 37, so that any tendency of the inner ball-races of the ball hearings to turn relative to the stud 32, is

slide 8 downward, which movement is opposed by the thumb-screw 21 which has threaded engagement with the offset portion 19 of the slide, with the lower end of the set screw in engagement with the plane surface '14 at the upper end of extension '13 of the bracket. Thus, downward movement of the thumb-screw moves the slide 8, and hence pulleys 9 and 10, upward, and increases the tension, of the belt, while upward movement ofsaidscrew permits the slide to be moved downward by the. pull of the belt upon said pulleys, and the tension ofthe belt is reduced accordingly.

To: assemble the bracket and the slide, with the two pulleys and the grease cups in placeon the slide (the diameter of the grease cups being less than the width of the opening in. the slot18in the bracket), the upper portion of the slide is passed through said slot from the side of the bracket at which the pulleys are to be located, and the slide is moved upward in said slot until the offset portion 19 of the slide, and the lower end In the use of my improved belt-tightener, I

there are no screws, bolts or other parts that must be loosened or otherwise manipulated in order to ermit adjustment of the positions of the id er pulleys, and the pull of the belt holds the upper end of the slide, and the ears 26, tightly in engagement with the bracket, and thereby keeps the faces of the pulleys ,9 and 10 in the desired alinement relative to the faces of the other pulleys over which the belt runs. The tendency of the pull of the belt on the upper pulley 9'is to hold the upper portion of the slide against the face of the extension 13 of the bracket, and that of the pull of the belt on the lower pulley 10 is to hold the ears 26 against the opposite face of the bracket, due {0 the overhung arrangement of said pul eys.

Various modifications of minor details of my improved belt-tightener doubtless readily will suggest themselves to those skilled in the art to which it appertains, but such modifications fall'within the scope of my inventive rights, and my invention is not to be construed as being limited to any details not specifically set forth in the appended claims.

Having thus described the invention, what I"claim as new, and seek to secure by Lett'ers Patent, is V 1. A belt-tightener, comprising a bracket, a slide carrying an idler pulley over which the belt passes and movable relative to said bracket substantially in the lineof pull of said belt upon said pulley, opposed faces of said slide being slidably engaged withopposite sides of said bracket, both of said faces being held in such engagement by the pull of the belt upon said idler pulley, and means for moving said slide counter to the pull. of the belt to increase the tension thereof.

"2. A belt-tightener, comprising the elements recited in claim 1, and having in addition thereto a secondidler pulley carried by the slide and over' which the belt passes,

the pull of the belt on the two pulleys tending to retain both faces of the slide in slidable engagement with the bracket.

3. A belt-tightener, comprising a slotted bracket, and a slide carrying two idler pulleys over which the belt passes and movable in the slot in said bracket with opposed faces of said slide engaging 0 posite sides of the bracket, the pull of the belt upon said pulleys tending to retain said slide in slidable engagement with both sides of said bracket, whereby said pulleys are held in predetermined alinement relative to other pulleys over which the belt passes.

4-. A belt-tightener, comprising a bracket;

a slide movable on said bracket and carrying an idler pulley over which the belt passes, said slide being free for adjustment substantially in the direction of the pull of the belt upon said pulle and having oppositely-facing portions a apted to engage op belt upon said pulley being adapted to hold said slide portions ositively against said In testimony whereof I aflix my signature.

THOMAS ELLIOTT.

2o) posite sides of the bracket, the pull of the a 

